Field of the Invention
The invention is directed to a power converting technique and more particularly, to a flyback-based power converter with a synchronous rectifier (SR) and a control method for the flyback-based power converter.
Description of Related Art
Power conversion apparatuses are mainly used in converting high-level and unregulated input voltages into an output voltage with low levels and good stability that can be suitable for various types of electronic devices. In this way, the power conversion apparatus is widely applied to electronic devices, such as computers, office automation equipment, industrial control equipment and communication instruments.
Among various types of power converters, a flyback-based power converter is commonly used. A main part of the power converter is a transformer including a primary winding and a secondary winding. Generally, a synchronous rectifier may be disposed at a secondary side of the transformer. Through the control on the synchronous rectifier, the circuit at the secondary side of the transformer may be turned on or turned off, such that the energy stored at the primary winding may be adaptively converted into a current based on Lenz's law to charge output capacitors at the secondary side of the transformer, and thereby, a stable output voltage may be generated.
Therefore, how to control the synchronous rectifier adaptively to reduce power loss occurring during power conversion would be one of the important subjects that the persons skilled in the art have to pay attention to.